Electronics-Related.com Blogs http://www.r4sdhccn.com/blogs.php Blogs on Electronics-Related.com http://www.r4sdhccn.com/blogs.php http://www.r4sdhccn.com/new2/images/icon_100px.png en-US Sat, 28 Dec 2019 04:32:42 +0000 1577507562 Part 11. Using -ve Latency DSP to Cancel Unwanted Delays in Sampled-Data Filters/Controllers http://www.r4sdhccn.com/showarticle/1280/part-11-using-ve-latency-dsp-to-cancel-unwanted-delays-in-sampled-data-filters-controllers Some applications demand zero-latency or zero unwanted latency signal processing. Negative...]]> Tue, 18 Jun 2019 13:49:50 +0000 Somewhat Off Topic: Deciphering Transistor Terminology http://www.r4sdhccn.com/showarticle/1272/somewhat-off-topic-deciphering-transistor-terminology I recently learned something mildly interesting about transistors, so I thought I'd share my new knowledge with you folks. Figure 1 shows a p-n-p transistor comprising a small block of n-type semiconductor sandwiched between two blocks of p-type semiconductor.

The terminology of "emitter" and "collector" seems appropriate, but did you ever wonder why the semiconductor block in the center is...]]> Wed, 29 May 2019 00:51:42 +0000 Free Goodies from Embedded World - Full Inventory and Upcoming Draw Live-Streaming Date http://www.r4sdhccn.com/showarticle/1244/free-goodies-from-embedded-world-full-inventory Chances are that you already know that I went to Embedded World a few weeks ago and came back with a bag full of "goodies".  Initially, my vision was to do a single draw for one person to win it all, but I didn't expect to come back with so much stuff and so many development kits.   Based on your feedback, it seems like you guys agree that It wouldn't make sense for one person...]]> Fri, 22 Mar 2019 15:11:43 +0000 Free Goodies from Embedded World - What to Do Next? http://www.r4sdhccn.com/showarticle/1234/free-goodies-at-embedded-world-what-to-do I told you I would go on a hunt for free stuff at Embedded World in order to build a bundle for someone to win.

]]> Wed, 06 Mar 2019 17:11:27 +0000 Back from Embedded World 2019 - Funny Stories and Live-Streaming Woes http://www.r4sdhccn.com/showarticle/1233/embedded-world-2019-live-streaming-report When the idea of live-streaming parts of Embedded World came to me,  I got so excited that I knew I had to make it happen.  I perceived the opportunity as a win-win-win-win.  

  • win #1 - Engineers who could not make it to Embedded World would be able to sample the huge event, 
  • win #2 - The organisation behind EW would benefit from the extra exposure
  • win #3 -...]]> Fri, 01 Mar 2019 08:03:25 +0000 Spread the Word and Run a Chance to Win a Bundle of Goodies from Embedded World http://www.r4sdhccn.com/showarticle/1232/spread-the-word Do you have a Twitter and/or Linkedin account?

    If you do, please consider paying close attention for the next few days to the EmbeddedRelated Twitter account and to my personal Linkedin account (feel free to connect).  This is where I will be posting lots of updates about how the EmbeddedRelated.tv live streaming experience is going at Embedded World.

    The most...]]> Thu, 21 Feb 2019 16:37:35 +0000 Launch of EmbeddedRelated.tv http://www.r4sdhccn.com/showarticle/1231/launch-of-embeddedrelated-tv With the upcoming Embedded Word just around the corner, I am very excited to launch the EmbeddedRelated.tv platform.  

    This is where you will find the schedule for all the live broadcasts that I will be doing from Embedded World next week.  Please note that the schedule will be evolving constantly, even during the show, so I suggest your refresh the page...]]> Thu, 21 Feb 2019 15:00:12 +0000 Live Streaming from Embedded World! http://www.r4sdhccn.com/showarticle/1227/embedded-world-2019-going-live For those of you who won't be attending Embedded World this year, I will try to be your eyes and ears by video streaming live from the show floor.   

    I am not talking improvised streaming from a phone, but real, high quality HD streaming with a high-end camera and a device that will bond three internet connections (one wifi and two cellular) to ensure a steady, and hopefully...]]> Wed, 13 Feb 2019 00:36:39 +0000 What to See at Embedded World 2019 http://www.r4sdhccn.com/showarticle/1226/what-to-see-at-embedded-world-2019 ]]> Tue, 05 Feb 2019 15:20:13 +0000 Feedback Controllers - Making Hardware with Firmware. Part 10. DSP/FPGAs Behaving Irrationally http://www.r4sdhccn.com/showarticle/1206/feedback-controllers-making-hardware-with-firmware-part-10-dsp-fpgas-behaving-irrationally This article will look at a design approach for feedback controllers featuring  low-latency "irrational" characteristics to enable the creation of physical components such as transmission lines. Some thought will also be given as to the capabilities of the currently utilized Intel Cyclone V, the new Cyclone 10 GX and the upcoming Xilinx Versal floating-point FPGAs/ACAPs....]]> Thu, 22 Nov 2018 14:56:32 +0000 The Least Interesting Circuit in the World http://www.r4sdhccn.com/showarticle/1200/the-least-interesting-circuit-in-the-world It does nothing, most of the time.

    It cannot compute pi. It won’t oscillate. It doesn’t light up.

    Often it makes other circuits stop working.

    It is… the least interesting circuit in the world.

    What is it?

    About 25 years ago, I took a digital computer architecture course, and we were each given use of an ugly briefcase containing a bunch of solderless breadboards...]]> Sun, 07 Oct 2018 22:11:02 +0000 Sensors Expo - Trip Report & My Best Video Yet! http://www.r4sdhccn.com/showarticle/1187/sensors-expo-my-story This was my first time at Sensors Expo and my second time in Silicon Valley and I must say I had a great time.  

    Before I share with you what I find to be, by far, my best 'highlights' video yet for a conference/trade show, let me try to entertain you with a few anecdotes from this trip.  If you are not interested by my stories or maybe don't have the...]]> Fri, 03 Aug 2018 20:30:32 +0000 Feedback Controllers - Making Hardware with Firmware. Part 9. Closing the low-latency loop http://www.r4sdhccn.com/showarticle/1184/feedback-controllers-making-hardware-with-firmware-part-9-closing-the-low-latency-loop It's time to put together the DSP and feedback control sciences, the evaluation electronics, the Intel Cyclone floating-point FPGA algorithms and the built-in control loop test-bed and evaluate some example designs. We will be counting the nanoseconds and looking for textbook performance in the creation of emulated hardware circuits. Along the way, there is a printed circuit board (PCB)...]]> Mon, 09 Jul 2018 14:26:22 +0000 Who else is going to Sensors Expo in San Jose? Looking for roommate(s)! http://www.r4sdhccn.com/showarticle/1169/who-else-is-going-to-sensors-expo-in-san-jose This will be my first time attending this show and I must say that I am excited. I am bringing with me my cameras and other video equipment with the intention to capture as much footage as possible and produce a (hopefully) fun to watch 'highlights' video. I will also try to film as many demos as possible and share them with you.

    I enjoy going to shows like this one as it gives me the...]]> Tue, 29 May 2018 15:15:57 +0000 Voltage - A Close Look http://www.r4sdhccn.com/showarticle/1172.php My first boss liked to pose the following problem when interviewing a new engineer.  “Imagine two boxes on a table one with a battery the other with a light.  Assume there is no detectable voltage drop in the connecting leads and the leads cannot be broken.  How would you determine which box has the light?  Drilling a hole is not allowed.?

    The answer is simple. You...]]> Wed, 23 May 2018 11:30:54 +0000 What is Electronics http://www.r4sdhccn.com/showarticle/1165.php One answer to the question posed by the title might be: "The understanding that allows a designer to interconnect electrical components to perform electrical tasks." These tasks can involve measurement, amplification, moving and storing digital data, dissipating energy, operating motors, etc. Circuit theory uses the sinusoidal relations between components, voltages,...]]> Thu, 03 May 2018 20:31:22 +0000 Crowdfunding Articles? http://www.r4sdhccn.com/showarticle/1154/upcoming-articles-maybe Many of you have the knowledge and talent to write technical articles that would benefit the EE community.  What is missing for most of you though, and very understandably so, is the time and motivation to do it.   

    But what if you could make some money to compensate for your time spent on writing the article(s)?  Would some of you find the motivation and...]]> Thu, 12 Apr 2018 16:17:50 +0000 How precise is my measurement? http://www.r4sdhccn.com/showarticle/1150/how-precise-is-my-measurement Some might argue that measurement is a blend of skepticism and faith. While time constraints might make you lean toward faith, some healthy engineering skepticism should bring you back to statistics. This article reviews some practical statistics that can help you satisfy one common question posed by skeptical engineers: “How precise is my measurement??As we’ll see, by understanding how...]]> Wed, 28 Mar 2018 18:12:58 +0000 Embedded World 2018 - More Videos! http://www.r4sdhccn.com/showarticle/1148/embedded-world-2018-more-videos After the interview videos last week, this week I am very happy to release two more videos taken at Embedded World 2018 and that I am proud of.  

    For both videos, I made extensive use of my two new toys, a Zhiyun Crane Gimbal and a Sony a6300 camera.

    The use of a gimbal like the Zhiyun makes a big difference in terms of making the footage look much more stable and...]]> Tue, 27 Mar 2018 20:38:33 +0000 Feedback Controllers - Making Hardware with Firmware. Part 8. Control Loop Test-bed http://www.r4sdhccn.com/showarticle/1144/feedback-controllers-making-hardware-with-firmware-part-8-feedback-loop-testbed This part in the series will consider the signals, measurements, analyses and configurations for testing high-speed low-latency feedback loops and their controllers. Along with basic test signals, a versatile IFFT signal generation scheme will be discussed and implemented. A simple controller under test will be constructed to demonstrate the analysis principles in preparation for the...]]> Wed, 21 Mar 2018 18:17:29 +0000 Embedded World 2018 - The Interviews http://www.r4sdhccn.com/showarticle/1146/embedded-world-2018-interviews-demos Once again this year, I had the chance to go to Embedded World in Nuremberg Germany.  And once again this year, I brought my video equipment to try and capture some of the most interesting things at the show.  

    Something new this year, I asked Jacob Beningo if he would partner with me in doing interviews with a few vendors.  I would operate the camera while Jacob would...]]> Wed, 21 Mar 2018 16:25:14 +0000 Feedback Controllers - Making Hardware with Firmware. Part 7. Turbo-charged DSP Oscillators http://www.r4sdhccn.com/showarticle/1126/feedback-controllers-making-hardware-with-firmware-part-7-turbo-powered-oscillators Comparisons will be made between implementations on Intel Cyclone V and Fri, 05 Jan 2018 11:55:33 +0000 Feedback Controllers - Making Hardware with Firmware. Part 6. Self-Calibration Related. http://www.r4sdhccn.com/showarticle/1116/feedback-controllers-making-hardware-with-firmware-part-6-self-calibration-related This article will consider the engineering of a self-calibration & self-test capability to enable the project hardware to be configured and its basic performance evaluated and verified, ready for the development of the low-latency controller DSP firmware and closed-loop applications. Performance specifications will be documented in due course, on the project website Sun, 03 Dec 2017 17:26:13 +0000 Feedback Controllers - Making Hardware with Firmware. Part 5. Some FPGA Aspects. http://www.r4sdhccn.com/showarticle/1111/feedback-controllers-making-hardware-with-firmware-part-5-some-fpga-aspects Tue, 14 Nov 2017 17:50:32 +0000 Feedback Controllers - Making Hardware with Firmware. Part 4. Engineering of Evaluation Hardware http://www.r4sdhccn.com/showarticle/1098/working-title Tue, 10 Oct 2017 13:24:18 +0000 Feedback Controllers - Making Hardware with Firmware. Part 3. Sampled Data Aspects http://www.r4sdhccn.com/showarticle/1085/blogs-steve-maslen-feedback-controllers-making-hardware-with-firmware-part-3-sampled-domain-aspects This article will continue to look at some aspects of the controllers and electronics needed to create emulated physical circuits with real-world connectivity and will look at the issues that arise in sampled-data controllers compared to continuous-domain controllers. As such, is not intended as an introduction to...]]> Sat, 09 Sep 2017 13:59:35 +0000 Finally got a drone! http://www.r4sdhccn.com/showarticle/1082/finally-got-a-drone As a reader of my blog, you already know that I have been making videos lately and thoroughly enjoying the process.  When I was in Germany early this summer (and went 280 km/h in a porsche!) to produce SEGGER's 25th anniversary video, the company bought a drone so we could get an aerial shot of the party (at about the 1:35 mark in this video).  Since then, I have been...]]> Mon, 28 Aug 2017 15:10:27 +0000 Feedback Controllers - Making Hardware with Firmware. Part 2. Ideal Model Examples http://www.r4sdhccn.com/showarticle/1081/blogs-steve-maslen-feedback-controllers-making-hardware-with-firmware-part-2-ideal-model-examples This article will describe models for simulating the systems and controllers for the hardware emulation application described in Part 1 of the series.

    • Part 1: Introduction
    • Part 2: Ideal Model Examples
    • Part 3: Sampled...]]> Thu, 24 Aug 2017 17:25:07 +0000 Feedback Controllers - Making Hardware with Firmware. Part I. Introduction http://www.r4sdhccn.com/showarticle/1077/making-hardware-with-firmware-science-engineering-and-applications This is the 1st in a series of articles looking at how we can use DSP and Feedback Control Sciences along with some mixed-signal electronics and number-crunching capability (e.g. FPGA), to create arbitrary (within reason) Electrical/Electronic Circuits with real-world connectivity. Of equal importance will be the evaluation of the functionality and...]]> Tue, 22 Aug 2017 16:24:21 +0000 SEGGER's 25th Anniversary Video http://www.r4sdhccn.com/showarticle/1071/segger-s-25th-anniversary-video Chances are you will find this video more interesting to watch if you take five minutes to first read the story of the week I spent at SEGGER's headquarters at the end of June.  

      The video is only a little more than 2 minutes long.  If you decide to watch it, make sure to go full screen and I would really love to read your thoughts about it in the comments down bellow.  Do...]]> Tue, 18 Jul 2017 18:11:37 +0000 Linear Feedback Shift Registers for the Uninitiated, Part II: libgf2 and Primitive Polynomials http://www.r4sdhccn.com/showarticle/1070/linear-feedback-shift-registers-for-the-uninitiated-part-2-libgf2-and-primitive-polynomials Last time, we looked at the basics of LFSRs and finite fields formed by the quotient ring \( GF(2)[x]/p(x) \).

      LFSRs can be described by a list of binary coefficients, sometimes referred as the polynomial, since they correspond directly to the characteristic polynomial of the quotient ring.

      Today we’re going to look at how to perform certain practical calculations in these finite...]]> Mon, 17 Jul 2017 04:12:13 +0000 Went 280km/h (174mph) in a Porsche Panamera in Germany! http://www.r4sdhccn.com/showarticle/1062/280kmh_in_a_Porsche Those of you who've been following my blog lately already know that I am going through some sort of mid-life crisis that involves going out there to meet people and make videos.  It all started with Embedded World early this year, then continued at ESC Boston a couple of months ago and the latest chapter just concluded as I returned from...]]> Mon, 10 Jul 2017 14:21:15 +0000 Linear Feedback Shift Registers for the Uninitiated, Part I: Ex-Pralite Monks and Finite Fields http://www.r4sdhccn.com/showarticle/1065/linear-feedback-shift-registers-for-the-uninitiated-part-i-ex-pralite-monks-and-finite-fields Later there will be, I hope, some people who will find it to their advantage to decipher all this mess.

      — Évariste Galois, May 29, 1832

      I was going to call this short series of articles “LFSRs for Dummies”, but thought better of it. What is a linear feedback shift register? If you want the short answer, the Mon, 03 Jul 2017 18:43:16 +0000 Going back to Germany! http://www.r4sdhccn.com/showarticle/1057/going-back-to-germany A couple of blog posts ago, I wrote that the decision to go to ESC Boston ended up being a great one for many different reasons.  I came back from the conference energized and really happy that I went.  

      These feelings were amplified a few days after my return when I received an email from Rolf Segger, the founder of SEGGER Microcontroller ( Tue, 13 Jun 2017 19:22:24 +0000 ESC Boston's Videos are Now Up http://www.r4sdhccn.com/showarticle/1054/esc-boston-s-videos-are-now-up In my last blog, I told you about my experience at ESC Boston and the few videos that I was planning to produce and publish.  Here they are, please have a look and any feedback (positive or negative) is appreciated. 

      Short Highlight

      This is a very short (one minute) montage of some of the footage that I shot at the show & conference.  In future shows, I absolutely need to...]]> Mon, 05 Jun 2017 13:53:50 +0000 Back from ESC Boston http://www.r4sdhccn.com/showarticle/1048/back-from-esc-boston NOT going to ESC Boston would have allowed me to stay home, in my comfort zone.

      NOT going to ESC Boston would have saved me from driving in the absolutely horrible & stressful Boston traffic1.

      NOT going to ESC Boston would have saved me from having to go through a full search & questioning session at the Canada Customs on my return2.

      Sun, 07 May 2017 00:40:31 +0000 Launch of Youtube Channel: My First Videos - Embedded World 2017 http://www.r4sdhccn.com/showarticle/1042/launch-of-youtube-channel-my-first-videos-embedded-world-2017 I went to Embedded World 2017 in Nuremberg with an ambitious plan; I would make video highlights of several exhibits (booths) to be presented to the *Related sites audience.  I would try to make the vendors focus their pitch on the essential in order to produce a one to three minutes video per booth.

      So far my experience with making videos was limited to family videos, so I knew I had...]]> Wed, 05 Apr 2017 16:27:00 +0000 The Other Kind of Bypass Capacitor http://www.r4sdhccn.com/showarticle/1021/the-other-kind-of-bypass-capacitor There’s a type of bypass capacitor I’d like to talk about today.

      It’s not the usual power supply bypass capacitor, aka decoupling capacitor, which is used to provide local charge storage to an integrated circuit, so that the high-frequency supply currents to the IC can bypass (hence the name) all the series resistance and inductance from the power supply. This reduces the...]]> Wed, 04 Jan 2017 03:34:59 +0000 New Comments System (please help me test it) http://www.r4sdhccn.com/showarticle/1003/please-help-me-test-the-new-comments-system I thought it would take me a day or two to implement, it took almost two weeks...

      But here it is, the new comments systems for blogs, heavily inspired by the forum system I developed earlier this year.  

      Which means that:

      • You can easily add images, either by drag and drop or through the 'Insert Image' button
      • You can add MathML, TeX and ASCIImath equations and they will be rendered with...]]> Tue, 04 Oct 2016 17:15:57 +0000 Use DPLL to Lock Digital Oscillator to 1PPS Signal http://www.r4sdhccn.com/showarticle/991/use-dpll-to-lock-digital-oscillator-to-1pps-signal There are occasions where it is desirable to lock a digital oscillator to an external time reference such as the 1PPS (One Pulse Per Second) signal output from a GPS receiver. One approach would be to synchronize a fixed frequency oscillator on the leading edge of the 1PPS signal. In many cases, this will result in adequate performance. However, in situations where simple...]]> Sun, 24 Jul 2016 12:57:11 +0000 Digital PLL's -- Part 2 http://www.r4sdhccn.com/showarticle/973/digital-pll-s-part-2 In Part 1, we found the time response of a 2nd order PLL with a proportional + integral (lead-lag) loop filter.  Now let’s look at this PLL in the Z-domain [1, 2].  We will find that the response is characterized by a loop natural frequency ωn and damping coefficient ζ. 

        Having a Z-domain model of the DPLL will allow us to do three things:

      • Compute the...]]> Wed, 15 Jun 2016 11:18:41 +0000 Digital PLL's -- Part 1 http://www.r4sdhccn.com/showarticle/967/digital-pll-s-part-1 Figure 1.1 is a block diagram of a digital PLL (DPLL).  The purpose of the DPLL is to lock the phase of a numerically controlled oscillator (NCO) to a reference signal.  The loop includes a phase detector to compute phase error and a loop filter to set loop dynamic performance.  The output of the loop filter controls the frequency and phase of the NCO,...]]> Tue, 07 Jun 2016 14:34:38 +0000 Stability or insanity http://www.r4sdhccn.com/showarticle/959.php I've just spent over two weeks getting ready to do my next video.  It was a combination of one of those vast underestimations one occasionally makes, combined with falling into a bit of an obsession.

        I am, at this point, not only wondering if it was worth it, but questioning my sanity in carrying on even when the going went beyond tough to just plain crazy.

        At any rate, a good video needs a...]]> Tue, 17 May 2016 06:22:20 +0000 PID Without a PhD http://www.r4sdhccn.com/showarticle/943/pid-without-a-phd I both consult and teach in the area of digital control. Through both of these efforts, I have found that while there certainly are control problems that require all the expertise I can bring to bear, there are a great number of control problems that can be solved with the most basic knowledge of simple controllers, without resort to any formal control theory at all.

        This article will tell...]]> Tue, 26 Apr 2016 18:18:10 +0000 3 Good News http://www.r4sdhccn.com/showarticle/930/3-good-news Last week, I announced a new and ambitious reward program that will be funded by the new Vendors Directory.

        This week, I am happy to announce that we have our firsts two sponsors!  Quantum Leaps & Abelon Systems have agreed to pay the sponsorship fee to be...]]> Wed, 09 Mar 2016 21:12:03 +0000 The New Forum is LIVE! http://www.r4sdhccn.com/showarticle/913/welcome-to-the-new-forum After months of hard word, I am very excited to introduce to you the new forum interface.  

        Here are the key features:

        1- Easily add images to a post by drag & dropping the images in the editor

        2- Easily attach files to a post by drag & dropping the files in the editor

        3- Add latex equations to a post and they will be rendered with Mathjax ( Thu, 18 Feb 2016 14:31:48 +0000 Ancient History http://www.r4sdhccn.com/showarticle/907/ancient-history The other day I was downloading an IDE for a new (to me) OS.  When I went to compile some sample code, it failed.  I went onto a forum, where I was told "if you read the release notes you'd know that the peripheral libraries are in a legacy download".  Well damn!  Looking back at my previous versions I realized I must have done that and forgotten about it.  Everything...]]> Mon, 18 Jan 2016 14:15:28 +0000 What IS an electron? http://www.r4sdhccn.com/showarticle/899.php When I was a student I got kicked out of a professor's office for having the gall to say that an electron was nothing more than a theory. I still believe that. It is an amazing and awesome theory, and the more we learn the more wonderous the theory becomes.

        The word electron first appeard in 1891 long after electricity had been in use. In 1897 the electron was discovered by J.J. Thompson...]]> Mon, 21 Dec 2015 15:27:43 +0000 The Art of Debugging http://www.r4sdhccn.com/showarticle/893.php Debugging electronics is similar to any technological process.  In theory we know how things are supposed to work, in reality they don't behave as expected.  The challenge of engineering boils down to making things work, and debugging is the fundamental task we use to go from lumps of sand to picosecond accurate switching networks.  Debugging is an art that requires a lot of...]]> Fri, 11 Dec 2015 16:13:29 +0000 Working of the first solid state amplifier http://www.r4sdhccn.com/showarticle/865.php

                                                 Fig. 1. One of the most popular operational amplifier 

        Whenever a circuit designer thinks about amplifier, the first think that pops up in his mind is that of operational amplifier (Op-Amp). The answer is simple op-amps are beautiful...]]> Tue, 01 Dec 2015 02:14:40 +0000 Basic hand tools for electronics assembly http://www.r4sdhccn.com/showarticle/870/handtools-for-electronics-assembly Though the software tools vary with different microcontrollers, many hardware tools are the same.

        If you are working on larger robotic or automotive systems, you will need a 3/8" and 1/2" drive socket set. There are occasions when even larger drive socket sets are needed. For small robots and taking things apart, the 1/4" drive socket set is useful. The sizes usually range from 5/32"...]]> Fri, 20 Nov 2015 05:35:03 +0000 Helping New Bloggers to Break the Ice: A New Ipad Pro for the Author with the Best Article! http://www.r4sdhccn.com/showarticle/849/breaking-the-ice Breaking the ice can be tough.  Over the years, many individuals have asked to be given access to the blogging interface only to never post an article.  Maybe they underestimated the time it takes to write a decent article, or maybe they got cold feet. I don't blame or judge them at all - how many times in my life have I had the intention to do...]]> Mon, 09 Nov 2015 19:16:19 +0000 Welcoming MANY New Bloggers! http://www.r4sdhccn.com/showarticle/837/welcoming-many-new-bloggers The response to the latest call for bloggers has been amazing and I am very grateful.

        In this post I present to you the individuals who, so far (I am still receiving applications at an impressive rate and will update this page as more bloggers are added),  have been given access to the blogging interface.  I am very pleased with the positive response and I...]]> Tue, 27 Oct 2015 21:28:04 +0000 Recruiting New Bloggers! http://www.r4sdhccn.com/showarticle/815/recruiting-new-bloggers Previous calls for bloggers have been very successful in recruiting some great communicators - Rick LyonsJason Sachs, Victor Yurkovsky, Mike Silva, Markus Nentwig Fri, 16 Oct 2015 14:17:01 +0000 How to Read a Power MOSFET Datasheet http://www.r4sdhccn.com/showarticle/809/How_to_Read_a_Power_MOSFET_Datasheet One of my pet peeves is when my fellow engineers misinterpret component datasheets. This happened a few times recently in separate instances, all involving power MOSFETs. So it’s time for me to get on my soapbox. Listen up!

        I was going to post an article on how to read component datasheets in general. But MOSFETs are a good place to start, and are a little more specific. I’m not the first...]]> Tue, 15 Sep 2015 04:54:39 +0000 Two Capacitors Are Better Than One http://www.r4sdhccn.com/showarticle/742/two-capacitors-are-better-than-one I was looking for a good reference for some ADC-driving circuits, and ran across this diagram in Walt Jung’s Op-Amp Applications Handbook:

        And I smiled to myself, because I immediately remembered a circuit I hadn’t used for years. Years! But it’s something you should file away in your bag of tricks.

        Take a look at the RC-RC circuit formed by R1, R2, C1, and C2....]]> Sun, 15 Feb 2015 20:36:24 +0000 Voltage Drops Are Falling on My Head: Operating Points, Linearization, Temperature Coefficients, and Thermal Runaway http://www.r4sdhccn.com/showarticle/730/voltage-drops-are-falling-on-my-head-operating-points-linearization-temperature-coefficients-and-thermal-runaway Today’s topic was originally going to be called “Small Changes Caused by Various Things”, because I couldn’t think of a better title. Then I changed the title. This one’s not much better, though. Sorry.

        What I had in mind was the Shockley diode equation and some other vaguely related subjects.

        My Teachers Lied to Me

        My introductory circuits class in...]]> Mon, 19 Jan 2015 15:26:00 +0000 Optimizing Optoisolators, and Other Stories of Making Do With Less http://www.r4sdhccn.com/showarticle/705/optimizing-optoisolators-and-other-stories-of-making-do-with-less It’s been a few months since I’ve rolled up my sleeves here and dug into some good old circuit design issues. I started out with circuit design articles, and I’ve missed it.

        Today’s topic will be showing you some tricks for how to get more performance out of an optoisolator. These devices — and I’m tempted to be lazy and call them “optos”, but...]]> Mon, 15 Dec 2014 02:20:54 +0000 Someday We’ll Find It, The Kelvin Connection http://www.r4sdhccn.com/showarticle/622/someday-we-ll-find-it-the-kelvin-connection You’d think it wouldn’t be too hard to measure electrical resistance accurately. And it’s really not, at least according to wikiHow.com: you just follow these easy steps:

        • Choose the item whose resistance you wish to measure.
        • Plug the probes into the correct test sockets.
        • Turn on the multimeter.
        • Select the best testing range.
        • Touch the multimeter...]]> Mon, 28 Jul 2014 14:20:59 +0000 10 Items of Test Equipment You Should Know http://www.r4sdhccn.com/showarticle/609/10-items-of-test-equipment-you-should-know When life gets rough and a circuit board is letting you down, it’s time to turn to test equipment. The obvious ones are multimeters and oscilloscopes and power supplies. But you know about those already, right?

          Here are some you may not have heard of:

        • Non-contact current sensors. Oscilloscope probes measure voltage. When you need to measure current, you need a different approach....]]> Sun, 22 Jun 2014 22:46:27 +0000 Specifying the Maximum Amplifier Noise When Driving an ADC http://www.r4sdhccn.com/showarticle/604/specifying-the-maximum-amplifier-noise-when-driving-an-adc I recently learned an interesting rule of thumb regarding the use of an amplifier to drive the input of an analog to digital converter (ADC). The rule of thumb describes how to specify the maximum allowable noise power of the amplifier [1].

          The Problem Here's the situation for an ADC whose maximum analog input voltage range is –VRef to +VRef. If we drive an ADC's analog input with an sine...]]> Mon, 09 Jun 2014 19:47:38 +0000 First-Order Systems: The Happy Family http://www.r4sdhccn.com/showarticle/590/first-order-systems-the-happy-family — Ле{ Ниaоxае{ич Тоxстой, Анна Каренина

          Happy families are all alike; every unhappy family is unhappy in its own way.

          — Lev Nicholaevich...]]> Sat, 03 May 2014 22:42:16 +0000 Lost Secrets of the H-Bridge, Part IV: DC Link Decoupling and Why Electrolytic Capacitors Are Not Enough http://www.r4sdhccn.com/showarticle/588/lost-secrets-of-the-h-bridge-part-iv-dc-link-decoupling-and-why-electrolytic-capacitors-are-not-enough Those of you who read my earlier articles about H-bridges, and followed them closely, have noticed there's some unfinished business. Well, here it is. Just so you know, I've been nervous about writing the fourth (and hopefully final) part of this series for a while. Fourth installments after a hiatus can bring bad vibes. I mean, look what it did to George Lucas: now we have Tue, 29 Apr 2014 05:50:43 +0000 April is Oscilloscope Month: In Which We Discover Agilent Offers Us a Happy Deal and a Sad Name http://www.r4sdhccn.com/showarticle/583/april-is-oscilloscope-month-in-which-we-discover-agilent-offers-us-a-happy-deal-and-a-sad-name Last month I wrote that March is Oscilloscope Month, because Agilent had a deal on the MSOX2000 and MSOX3000 series scopes offering higher bandwidth at lower prices. I got an MSOX3034 oscilloscope and saved my company $3500! (Or rather, I didn't save them anything, but I got a 350MHz scope at a 200MHz price.)

          The scope included a free 30-day trial for each of the application software modules....]]> Sat, 19 Apr 2014 18:20:52 +0000 March is Oscilloscope Month ?and at Tim Scale! http://www.r4sdhccn.com/showarticle/540/test I got my oscilloscope today.

          Maybe that was a bit of an understatement; I'll have to resort to gratuitous typography:


          Those of you who are reading this blog may remember I made a post about two years ago about searching for the right oscilloscope for me. Since then, I changed jobs and have been getting situated in...]]> Thu, 06 Mar 2014 13:44:21 +0000 Efficiency Through the Looking-Glass http://www.r4sdhccn.com/showarticle/533/efficiency-through-the-looking-glass If you've ever designed or purchased a power supply, chances are you have had to work with efficiency calculations. I can remember in my beginning electronic circuits course in college, in the last lecture when the professor was talking about switching power converters, and saying how all of a sudden you could take a linear regulator that was 40% efficient and turn it into a switching...]]> Sun, 08 Dec 2013 19:09:45 +0000 How to Estimate Encoder Velocity Without Making Stupid Mistakes: Part II (Tracking Loops and PLLs) http://www.r4sdhccn.com/showarticle/530/how-to-estimate-encoder-velocity-without-making-stupid-mistakes-part-ii-tracking-loops-and-plls Yeeehah! Finally we're ready to tackle some more clever ways to figure out the velocity of a position encoder. In part I, we looked at the basics of velocity estimation. Then in my last article, I talked a little about what's necessary to evaluate different kinds of algorithms. Now it's time to start describing them. We'll cover tracking loops and phase-locked loops in this article, and...]]> Mon, 18 Nov 2013 02:38:46 +0000 Another 10 Circuit Components You Should Know http://www.r4sdhccn.com/showarticle/522/another-10-circuit-components-you-should-know It's that time again to review all the oddball goodies available in electronic components. These are things you should have in your bag of tricks when you need to design a circuit board. If you read my previous posts and were looking forward to more, this article's for you!

          1. Bus switches

          I can't believe I haven't mentioned bus switches before. What is a bus...]]> Wed, 30 Oct 2013 15:58:37 +0000 Short Takes (EE Shanty): What shall we do with a zero-ohm resistor? http://www.r4sdhccn.com/showarticle/509/short-takes-ee-shanty-what-shall-we-do-with-a-zero-ohm-resistor In circuit board design you often need flexibility. It can cost hundreds or thousands of dollars to respin a circuit board, so I need flexibility for two main reasons:

          • sometimes it's important to be able to use one circuit board design to serve more than one purpose
          • risk reduction: I want to give myself the option to add in or leave out certain things when I'm not 100% sure I'll need...]]> Sat, 19 Oct 2013 23:53:26 +0000 BGA and QFP at Home 1 - A Practical Guide. http://www.r4sdhccn.com/showarticle/499/fpga-prototyping-at-home-1-a-practical-guide It is almost universally accepted by the hobbyists that you can't work with high-density packages at home.  That is entirely incorrect.  I've been assembling and reflowing BGA circuit boards at home for a few years now.  BGAs and 0.5mm-pitch QFPs are well within the realm of a determined amateur. 

            This series of articles presents practical information on designing and...]]> Sun, 13 Oct 2013 18:27:30 +0000 3 LEDs powered by fingers - puzzle http://www.r4sdhccn.com/showarticle/496.php I would like to present my last puzzle design.

            If you like such puzzles, I invite you to watch the movie below.

            How does it work ?

            Tue, 08 Oct 2013 09:43:12 +0000
            Series circuit - 3 LEDs http://www.r4sdhccn.com/showarticle/484.php How does it work???



            Tue, 24 Sep 2013 18:17:09 +0000
            Video: The PN Junction. How Diodes Work? http://www.r4sdhccn.com/showarticle/482.php Really cool video on PN Junctions


            Fri, 20 Sep 2013 11:30:26 +0000
            Lost Secrets of the H-Bridge, Part III: Practical Issues of Inductor and Capacitor Ripple Current http://www.r4sdhccn.com/showarticle/424/lost-secrets-of-the-h-bridge-part-3 We've been analyzing the ripple current in an H-bridge, both in an inductive load and the DC link capacitor. Here's a really quick recap; if you want to get into more details, go back and read part I and part II until you've got equations coming out of your ears. I promise there will be a lot less grungy math in this post. So let's get most of it out of the way:

            Switches QAH...]]> Sat, 24 Aug 2013 05:32:02 +0000 Lost Secrets of the H-Bridge, Part II: Ripple Current in the DC Link Capacitor http://www.r4sdhccn.com/showarticle/422/lost-secrets-of-the-h-bridge-part-2 In my last post, I talked about ripple current in inductive loads.

            One of the assumptions we made was that the DC link was, in fact, a DC voltage source. In reality that's an approximation; no DC voltage source is perfect, and current flow will alter the DC link voltage. To analyze this, we need to go back and look at how much current actually is being drawn from the DC link. Below is an...]]> Sun, 28 Jul 2013 16:51:44 +0000 Lost Secrets of the H-Bridge, Part I: Ripple Current in Inductive Loads http://www.r4sdhccn.com/showarticle/421/lost-secrets-of-the-h-bridge-part-1-ripple-current-in-inductive-loads So you think you know about H-bridges? They're something I mentioned in my last post about signal processing with Python.

            Here we have a typical H-bridge with an inductive load. (Mmmmm ahhh! It's good to draw by hand every once in a while!) There are four power switches: QAH and QAL connecting node A to the DC link, and QBH and QBL connecting node B to the DC link. The load is connected...]]> Mon, 08 Jul 2013 03:56:48 +0000 Isolated Sigma-Delta Modulators, Rah Rah Rah! http://www.r4sdhccn.com/showarticle/338/isolated-sigma-delta-modulators-rah-rah-rah I recently faced a little "asterisk" problem, which looks like it can be solved with some interesting ICs. 

            I needed to plan out some test instrumentation to capture voltage and current information over a short period of time. Nothing too fancy, 10 or 20kHz sampling rate, about a half-dozen channels sampled simultaneously or near simultaneously, for maybe 5 or 10 seconds.

            Here's the...]]> Thu, 25 Apr 2013 06:38:33 +0000 Oscilloscope review: Hameg HMO2024 http://www.r4sdhccn.com/showarticle/336/oscilloscope-review-hameg-hmo2024 Last year I wrote about some of the key characteristics of oscilloscopes that are important to me for working with embedded microcontrollers. In that blog entry I rated the Agilent MSOX3024A 4-channel 16-digital-input oscilloscope highly.

            Since then I have moved to a different career, and I am again on the lookout for an oscilloscope. I still consider the Thu, 28 Mar 2013 04:00:20 +0000 Two jobs http://www.r4sdhccn.com/showarticle/313/two-jobs For those of you following closely embeddedrelated and the other related sites, you might have noticed that I have been less active for the last couple of months, and I will use this blog post to explain why. The main reason is that I got myself involved into a project that ended up using a better part of my cpu than I originally thought it would.

            edit - video of the event:

            Wed, 05 Dec 2012 13:52:05 +0000
            Have You Ever Seen an Ideal Op-Amp? http://www.r4sdhccn.com/showarticle/299/have-you-ever-seen-an-ideal-op-amp Somewhere, along with unicorns and the Loch Ness Monster, lies a small colony of ideal op-amps. Op-amp is short for operational amplifier, and we start our education on them by learning about these mythical beasts, which have the following properties:

            • Infinite gain
            • Infinite input impedance
            • Zero output impedance

            And on top of it all, they will do whatever it takes to change their output...]]> Mon, 30 Apr 2012 21:49:45 +0000 Hot Fun in the Silicon: Thermal Testing with Power Semiconductors http://www.r4sdhccn.com/showarticle/300/hot-fun-in-the-silicon-thermal-testing-with-power-semiconductors Here's a trick that is useful the next time you do thermal testing with your MOSFETs or IGBTs.

            Thermal testing?!

            Yes, that's right. It's important to make sure your power transistors don't overheat. In the datasheet, you will find some information that you can use to estimate how hot the junction inside the IC will get.

            Let's look at an example. Here's a page from the Sat, 21 Apr 2012 00:59:43 +0000 10 More (Obscure) Circuit Components You Should Know http://www.r4sdhccn.com/showarticle/293/10-more-obscure-circuit-components-you-should-know The interest in my previous article on obscure but useful electronics parts, "10 Circuit Components You Should Know" was encouraging enough that I thought I would write a followup. So here are another 10:

            1. "Ideal Diode" controllers

            Load-sharing circuits use diodes tied together at their cathode terminal to take the most positive voltage among the sources and connect it to a load. Works...]]> Sun, 05 Feb 2012 18:06:52 +0000 Oscilloscope Dreams http://www.r4sdhccn.com/showarticle/268/oscilloscope-dreams My coworkers and I recently needed a new oscilloscope. I thought I would share some of the features I look for when purchasing one.

            When I was in college in the early 1990's, our oscilloscopes looked like this:

            Now the cathode ray tubes have almost all been replaced by digital storage scopes with color LCD screens, and they look like these:

            Oscilloscopes...]]> Sun, 15 Jan 2012 03:14:49 +0000 Stairway to Thévenin http://www.r4sdhccn.com/showarticle/273/stairway-to-th-venin This article was inspired by a recent post on reddit asking for help on Thévenin and Norton equivalent circuits.

            (With apologies to Mr. Thévenin, the rest of the e's that follow will remain unaccented.)

            I still remember my introductory circuits class on the subject, roughly as follows:

            (NOTE: Do not get scared of what you see in the rest of this section. We're going...]]> Sat, 31 Dec 2011 15:55:10 +0000 10 Circuit Components You Should Know http://www.r4sdhccn.com/showarticle/289/10-circuit-components-you-should-know Chefs have their miscellaneous ingredients, like condensed milk, cream of tartar, and xanthan gum. As engineers, we too have quite our pick of circuits, and a good circuit designer should know what's out there. Not just the bread and butter ingredients like resistors, capacitors, op-amps, and comparators, but the miscellaneous "gadget" components as well.

            Here are ten circuit components you...]]> Mon, 28 Nov 2011 02:26:43 +0000 Analog-to-Digital Confusion: Pitfalls of Driving an ADC http://www.r4sdhccn.com/showarticle/287/analog-to-digital-confusion-pitfalls-of-driving-an-adc Imagine the following scenario:You're a successful engineer (sounds nice, doesn't it!) working on a project with three or four circuit boards. More than even you can handle, so you give one of them over to your coworker Wayne to design. Wayne graduated two years ago from college. He's smart, he's a quick learner, and he's really fast at designing schematics and laying out circuit boards. It's...]]> Sat, 19 Nov 2011 22:20:30 +0000 Complexity in Consumer Electronics Considered Harmful http://www.r4sdhccn.com/showarticle/274/complexity-in-consumer-electronics-considered-harmful I recently returned from a visit to my grandmother, who lives in an assisted living community, and got to observe both her and my frustration first-hand with a new TV. This was a Vizio flatscreen TV that was fairly easy to set up, and the picture quality was good. But here's what the remote control looks like:

            You will note:

            • the small lettering (the number buttons are just under 1/4 inch...]]> Sun, 02 Oct 2011 01:32:38 +0000 Which MOSFET topology? http://www.r4sdhccn.com/showarticle/278/which-mosfet-topology A recent electronics.StackExchange question brings up a good topic for discussion. Let's say you have a power supply and a 2-wire load you want to be able to switch on and off from the power supply using a MOSFET. How do you choose which circuit topology to choose? You basically have four options, shown below:

              From left to right, these are:

            • High-side switch,...]]> Fri, 02 Sep 2011 01:43:09 +0000 Thermistor signal conditioning: Dos and Don'ts, Tips and Tricks http://www.r4sdhccn.com/showarticle/269/thermistor-signal-conditioning-dos-and-don-ts-tips-and-tricks In an earlier blog entry,  I mentioned this circuit for thermistor signal conditioning:

              It is worth a little more explanation on thermistor signal conditioning; it's something that's often done poorly, whereas it's among the easiest applications for signal conditioning.

              The basic premise here is that there are two resistors in a voltage divider: Rth is the thermistor, and Rref is a...]]> Thu, 16 Jun 2011 02:45:44 +0000 Real-time clocks: Does anybody really know what time it is? http://www.r4sdhccn.com/showarticle/267/real-time-clocks-does-anybody-really-know-what-time-it-is We recently started writing software to make use of a real-time clock IC, and found to our chagrin that the chip was missing a rather useful function, namely elapsed time in seconds since the standard epoch (January 1, 1970, midnight UTC).Let me back up a second.A real-time clock/calendar (RTC) is a micropower chip that has an oscillator on it that keeps counting time, independent of main...]]> Mon, 30 May 2011 02:00:39 +0000 Byte and Switch (Part 2) http://www.r4sdhccn.com/showarticle/259/byte-and-switch-part-2 In part 1 we talked about the use of a MOSFET for a power switch. Here's a different circuit that also uses a MOSFET, this time as a switch for signals:

              We have a thermistor Rth that is located somewhere in an assembly, that connects to a circuit board. This acts as a variable resistor that changes with temperature. If we use it in a voltage divider, the midpoint of the voltage divider...]]> Sat, 07 May 2011 21:14:41 +0000 Byte and Switch (Part 1) http://www.r4sdhccn.com/showarticle/257/byte-and-switch-part-1 Imagine for a minute you have an electromagnet, and a microcontroller, and you want to use the microcontroller to turn the electromagnet on and off. Sounds pretty typical, right?We ask this question on our interviews of entry-level electrical engineers: what do you put between the microcontroller and the electromagnet?We used to think this kind of question was too easy, but there are a...]]> Wed, 27 Apr 2011 01:30:29 +0000 3